Envelope opening machine

ABSTRACT

Envelopes are conveyed one at a time from a hopper to a horizontally disposed transport wheel which conveys each envelope to a first station where the side edges of the envelope are carbonized, a second station where the top edge of the envelope is carbonized and a third station where the envelope is removed from the transport wheel. Thereafter, the thusly treated envelope is manipulated by an apparatus which peels back one panel of the envelope to expose the contents thereof. Control means are provided for ensuring proper operation of the envelope opening machine.

United States Patent Pierce et al.

[ June 10, 1975 [54] ENVELOPE OPENING MACHINE 3322.523 7/l974 Russell et a! i. 53/381 R l75| lnventors: Edwin F. Pierce, Bessemer; Larry I w R0berts Fairfidd; Lehmd Primary EXUH1|HF-TFZ1VIS S. McGehee Maddox, Hueytown all of Ala. I73] Assignee: AmePO-Matic Corporation, l l ABSTRACT Bessemer- Am Envelopes are conveyed one at a time from a hopper {22] Filed July L 1974 to a horizontally disposed transport wheel which conveys each envelope to a first station where the side l 1 p N93 484,368 edges of the envelope are carbonized, a second station where the top edge of the envelope is carbonized and [52] CL 53/381 83/9i2 a third station where the envelope is removed from [51 I 1365b 61/00 the transport wheel. Thereafter, the thusly treated en- [58] Field of Search 53/38l R; 83/912 VElOPE is manipulated y an apparatus which peels back one panel of the envelope to expose the contents 56] References Cited thereof. Control means are provided for ensuring UNITED STATES PATENTS proper operation of the envelope opening maehine. 3,] I6 7I8 H1964 Krupotich et ul o 53/38] R 15 Claims, 18 Drawing Figures M //z /04 m2 4 90 10 T;

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FATENTEBJUH 10 R975 ENVELOPE OPENING MACHINE The present invention is directed to an envelope opening machine and more particularly to an envelope opening machine which is capable of automatically opening up to 3600 pieces of mail per hour. The envelope opening machine of the present invention constitutes a mechanized mailroom and is particularly useful for users who receive large volumes of mail each day.

The envelope epening machine of the present inven tion will substantially lower labor costs and overhead. Not only are three sides of the envelope opened. but the contents of the envelope are thereafter exposed and mechanically conveyed to a location wherein the contents may be removed and separated. The envelope opening machine of the present invention is also easy to operate and does not require any operating personnel other than one operator to feed the envelopes into the machine and the operators associated with the discharge assembly line for removing the contents of the envelopes from the envelopes.

In the envelope opening machine of the present invention, a stack of envelopes are stored in a hopper and are automatically removed one at a time from the hopper. The envelopes are conveyed to a horizontally disposed transport wheel which transports each envelope to a first station where the side edges of the envelope are burned, a second station where the top edge of the envelope is burned and to a third station where the en velope is removed from the transport wheel. Thereafter, the thusly treated envelope is automatically moved to an envelope opening section wherein a means forming a part of the machine automatically manipulates one of the envelope panels to expose the contents thereof.

It is, therefore, an object of the present invention to provide a novel envelope opening machine which is automatic and reliable.

It is another object of the present invention to pro vide an automatic envelope opening machine which carbonizes or burns three sides of an envelope and then exposes the contents of the envelope.

It is a further object of the present invention to provide an automatic envelope opening machine which burns or carbonizes three sides of an envelope without damaging the contents thereof.

It is a still further object of the present invention to provide an automatic envelope opening machine which is capable of reliable operation at speeds up to 3600 envelopes per hour.

For the purpose of illustrating the present invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is a side sectional view of a letter opening machine in accordance with the present invention.

FIG. 2 is a sectional view taken along the line 2 2 in FIG. 1.

FIG. 3 is a sectional view taken along the line 3 3 in FIG. 1.

FIG. 4 is a sectional view taken along the line 4 4 in FIG. 1, the hopper. located at the top of FIG. 1, being removed, however, for clarity.

FIG. 5 is a sectional view taken along the line 5 5 in FIG. 3.

FIG. 6 is a perspective view of an envelope guide means employed with the present invention.

FIG. 7 is a sectional view taken along the line 7 7 in FIG. 1.

FIG. 8 is a sectional view taken along the line 8 8 in FIG. 7.

FIG. 9 is a sectional view taken along the line 9 9 in FIG. 1.

FIG. I0 is an exploded sectional view of the envelope opening mechanism.

FIG. 11 is a perspective view of a modified form of an envelope hopper useful with the present invention.

FIG. I2 is an exploded partial perspective view of one end of an envelope edge carbonizing means.

FIG. [3 is a perspective view of an envelope to be processed by the envelope opening machine of the present invention.

FIG. 14 is a perspective view of an envelope having two side edges thereof which have been carbonized by the envelope opening machine of the present invention.

FIG. 15 is a perspective view of an envelope having three side edges thereof which have been carbonized by the envelope opening machine of the present invention.

FIG. 16 shows the envelope of FIG. IS with one panel manipulated to as to expose the contents of the envelope.

FIG. 17 is a block diagram of a control circuit for controlling the operation of the envelope opening machine of the present invention, and

FIG. 18 is a chart showing the timing sequence for the control circuit of FIG. 17.

Referring now to the drawings in detail, wherein like numerals indicate like elements, there is shown in FIGv I a side sectional view of a letter opening machine in accordance with the present invention and designated generally as 10. The machine 10 includes a support frame designated generally as 12 which supports the various components of the machine. The machine can be considered to be generally composed of three oper ating sections: an envelope feed section designated generally as 100, an envelope transport and carboniz ing section designated generally as 200 and an envelope opening section designated generally as 400. Driving power for most of the moving elements of the machine is provided by a continuously operating motor 14 mounted on plate 16 which is secured in a known manner to frame 12. Power is transmitted to the various elements through a series of chains 18-22, sprockets 2434, and pulleys which will be more fully described below.

A stack of envelopes 112 each being similar to the envelope 113 shown in FIG. 13 are manually placed in the hopper I02 located in the envelope feed section 100. The hopper 102 has a side wall 104, a downwardly inclined bottom wall 106 and an end wall 108. End wall I08 has a plurality of vertical slot shaped openings I10 therein which are adapted to periodically receive feed belts H6 and 116'. An opening III in bottom wall 106 is large enough to allow one of the envelopes in stack 112 to pass therethrough. A weight in the form of a roller 114 which is adapted to freely roll on the downwardly inclined bottom wall I06 helps maintain the envelopes 112 in their upright position and further helps force the envelopes against the end wall 103.

The remaining parts of the envelope feed section are comprised essentially of a plurality of feed belts, drive belts and drive wheels which, in the manner to be more fully described below, convey the envelopes 112 from the hopper 102 to the envelope transport and carbonizing section 200. As shown more clearly in FIGS. 3 and 4, these belts and wheels are arranged in symmetrical pairs about the vertical center of the envelope feed section 100. Accordingly, the following description will be directed primarily towards the envelope feed elements shown in the left half of FIGS. 3 and 4, it being under stood, however, that the corresponding elements shown in the righthand side of each Figure, which corresponding elements are correspondingly identified by primed numerals, are constructed and function in the same manner as those being described.

As most clearly shown in FIG. I, the envelopes 112 are transferred from the hopper 102 by continuously driven endless feed belt 116. Feed belt 116 is mounted about idler pulleys 118, 120, 122 and 124 and is moved in the direction shown by the arrows by drive pulley 126. A pair of idler pulleys 128 and 130, rotatably mounted on block 132 engage the feed belt 116 and with the aid of solenoid 134 are adapted to selectively move the feed belt 116 through opening 110 into frietional contact with the first envelope in the stack of envelopes 112 positioned within the hopper 102.

At the proper time, which is controlled by the control circuit 500 to be more fully described below, solenoid 134, mounted on support plate 136, is energized thereby moving rollers 128 and 130 outwardly or to the left as shown in FIG. 1. This movement of rollers 128 and 130 causes feed belt 116 to frictionally engage the first envelope in the stack of envelopes 112 and move it downwardly through the opening 111 at the bottom of the hopper 102. As the feed belt 116 continues to move the envelope 112 downwardly, the envelope 112 is forced through the gap between idler roller 138 and kick back roller 140. Located immediately below idler roller 138 and kick back roller 140 are a pair of feed rollers 142 and 144 each of which has a sponge rubber surface thereon. As the feed belt 116 moves the envelope 112 between idler roller 138 and kick back roller 140 the leading edge of the envelope 112 enters the nip between feed rollers 142 and 144 and is driven by these feed rollers downwardly into one of the slots 208 in wheel 202 of the envelope transport and carbonizing section 200. As best seen in FIG. 1, the feed belt 116 is arranged to be substantially parallel to the path of movement of the envelope as it approaches the wheel 202 thereby acting as a guide means for insuring that the envelope is properly aligned with the slot 208. A side guide 146 is also provided along the path of travel of the envelope in order to prevent the envelope from moving sideways. As best seen in FIG. 6, the guide 146 includes a vertical portion and a flared top portion 148 which helps guide the envelope into the vertical portion. The guide 146 is securely fixed to a slide portion 150 which is slidable on support bar 152. By this arrangement, the guide 146 can be moved inwardly or outwardly to adjust for various size envelopes. Once the guide 146 is moved to its proper position, it is securely held there by set screw 154.

Referring again to FIG. 1 it can be seen that the gap between idler roller 138 and kick back roller 140 is adjusted to be approximately equal to the thickness of one envelope. Accordingly. if more than one envelope should descend into the gap, the forwardmost envelope would be kicked back upwardly by the reversely rotating kick back roller 140. Furthermore, as will be more clearly shown below, kick back roller 140 rotates at a faster rate than feed belt 116 and feed rollers 142 and 144 to ensure that the forward envelope will be kicked back if more than one envelope should enter the gap. Under normal conditions, however, the envelope would not contact kick back roller since the gap between idler roller 138 and kick back roller 140 is substantially equal to the thickness of the envelope. Accordingly, one envelope would pass freely through the gap.

In order to accommodate envelopes of various thicknesses, the gap between idler roller 138 and kick back roller 140 is adjustable. To this end, idler roller 138 is rotatably mounted on a horizontally disposed shaft at one end of a lever 156. Lever 156 is pivotally mounted on block 158 (see FIG. 4) by pivot pin 160. The other end of lever 156 is connected to a spring 162 which in turn is connected to a screw 164 carried by bracket 166 mounted on support plate 136. Accordingly, the force of spring 162 causes idler roller 138 to move toward kick back roller 140. A screw 168 threaded through support plate 136 acts as an adjustable stop means for the lever 156. Accordingly, the gap between idler roller 138 and kick back roller 140 is easily adjusted by turning screw 168.

FIGS. 3 and 4 show the manner in which the elements of the envelope feed section 100. described above, are mounted. In each of these figures, the envelope hopper 102 has been removed for clarity. As can be seen from these figures, substantially all of the elements of the envelope feed section 100 are located between and supported by a pair of upwardly extending side walls 168 and 168'. As shown in FIG. 1, these upwardly extending side walls 168 and 168' are vertical while the various components of the feed section 100 are supported by these walls 168 and 168' so as to be inclined slightly rearwardly. These side walls 168 and 168 are rigidly secured to the main frame 12 in a manner well known in the art.

Adjacent the upper ends of the side walls and extending horizontally between the two walls 168, 168' is the support plate 136. The support plate 136 is secured to the side walls 168 and 168' by bolts 172 and 172'. As stated above, solenoid 134 is secured to the support plate 136 adjacent the center thereof. In addition, block 158 which pivotally supports lever 156 is secured to the support plate 136 by bolts 174. Each idler pulley for feed belt 116 is rotatably supported at the upper end of support plate 136 by bracket 176 and appropriate bearings (not shown) carried by bracket 176.

Extending between side walls 168 and 168' are a plurality of rotatably mounted horizontally disposed shafts supported on the side walls by suitable bearings. As best seen in FIG. 4, shaft 178, upon which are mounted drive pulleys 126 and 126' extends through side wall 168' and terminates in a suitable sprocket (not shown). Chain 22 passes over said sprocket to provide drive power to shaft 178 and to the entire envelope feed section 100. Also connected to shaft 178 and immediately adjacent the sprocket and chain 22 is a pulley 180.

A drive belt 182 transfers the rotary motion of shaft 178 from pulley to pulley 183 secured to the end of shaft 184 which supports feed rollers 142 and 142'. Shaft 184 also extends through side wall 168 and terminates in a gear 185. Gear 185 meshes with gear 186 which is secured to the end of shaft 187 upon which is carried feed rollers 144 and 144. Since gears 185 and 186 are the same size and have the same number of teeth. feed rollers 142 and 142' rotate at the same speed as feed rollers 144 and 144'. Howewr. as a result of the gears 185 and 186, these rollers are caused to rotate in opposite directions as shown by the arrows in H0. 1. Also connected to shaft 187 is a second and smaller gear 188, see FIG. 5.

Gear 188 meshes with an even smaller gear 189 secured to the end of shaft 190 which carries kick back rollers 140 and 140. As a result of the position and relative sizes of these gears, kick back rollers 140 and 140' are caused to rotate at a greater speed than rollers 144 and 144' and in a direction opposite to the direction of rotation of the rollers 144, 144' as shown in FIG. 1.

In addition to the driven shafts described above, shafts are also provided for idler pulleys 120 and 122 such as shaft 192 shown in FIG. 4. it will be understood that a similar shaft is provided for idler pulley 122. It should also be understood that, while not specifically described, each of the rotating shafts described above are supported by suitable bearings which are well known in the art.

It can also be seen FIG. 3 that support bar 152 for en velope guide means 146 and 146' is secured to side walls 168 and 168' by screws [94 and 194'. An envelope 113A is shown in phantom in FIG. 3 between the guides 146 and 146'. In this position, the envelope has passed through the envelope feed section 100 and is located in one of the slots 208 of the wheel 202 in the envelope transport and carbonizing section 200.

The envelope transport and carbonizing section 200 of the letter opening machine is comprised essentially of a transport wheel 202, a plurality of carbonizing means for destroying the edges of the envelopes and a take-off belt for removing the envelopes from the transport wheel 202. Similar to the envelope feed sec tion 100, the envelope transport and carbonizing section 200 is composed of a plurality of identical elements and accordingly the following description will be directed primarily towards one set of these elements. It being understood that the remaining elements, not specifically described, are substantially the same as those being described and function in exactly the same manner.

The envelope transport wheel 202 is composed of a plurality of identical wheels. Each wheel includes a hub portion 204, a plurality of spokes 206 equiangularly spaced about the hub 204 and a radially extending slot 208 in each of the spokes 206. The open end of each slot 208 is tapered outwardly as shown at 210. This facilitates the entry and exit of the envelopes to and from the slot 208 in wheel 202. Transport wheel 202 is rotatably mounted by horizontally disposed shaft 213 having one end secured to side frame portion 212 through a suitable bearing such as shown at 214. A stepping motor 218, controlled by the control circuit 500, supports the other end of shaft 213 and selectively moves the transport wheel 202 intermittently through the several operating stations A-D and the several nonoperative stations EJ in the direction shown by the arrow in FIG. 1. At operating position A, an envelope 113 is fed into the slot 208 in the spokes 206. The transport wheel 202 is then moved to a position B where both side edges of the envelope 113 are simultaneously destroyed by carbonizing means 220 and 220 An envelope 113B with its side edges destroyed by carbonizing means 220 and 220' is shown in FIG. 14.

As best shown FIGS. 7 and 8, the side edge carbonizing means 220 and 220' are adapted to move inwardly toward the envelope 11313 to destroy the side edges thereof and outwardly away from the envelope 1 138 to allow the envelope 1138 to proceed to the next station. Each side edge carbonizing means such as means 220 is secured to a plate 222 through a heat insulating means 224 and bolts 226. Plate 222 is fixedly connected to a pair ofslide bearings 228 and 230 which are adapted to slide linearly on slide rods 232 and 234. respectively. Slide rods 232 and 234 are securely fastened to a support bracket 236 by screws 238 and 240. Shock absorbing stopper means 242, 244, 246 and 248 are arranged at each end of each of the slide rods 232 and 234 in order to limit the sliding movement of the slide bearings 228 and 230. Connected between slide bearings 228 and 230 is a joining rod 250 having a reduced diameter portion 252 intermediate the ends thereof. The forked end 254 of a lever 256 slidably engages the reduced diameter portion 252 of joining rod 250.

At a point 258, remote from the forked end 254, lever 256 is pivotably secured to a support bracket 260. A pair of solenoids 262 and 264 are also mounted on support brackets 260 and are adapted to engage lever 256 on opposite sides of pivot point 258. Accordingly. when solenoid 162 is energized, lever 256 causes side edge carbonizing means 220 to slide outwardly away from envelope 113B and when solenoid 264 is energized, lever 256 causes side edge carbonizing means 220 to move inwardly toward envelope 1138.

As best shown in FIGS. 8 and 12, each edge carbonizing means 220 includes a housing composed of side wall portions 266 and 268 having inwardly flanged end portions such as 270 and 272. Contained within the housing is an electric heating element 274 enclosed within a metalic holder 276. The metalic holder 276 has a V-groove 278 which is adapted to engage the side edge of envelope 1138 for carbonizing or destroying the edge of the envelope. A thermistor 279 is mounted within the metalic holder 276 adjacent the V-groove 278. Thermistor 279 is connected to a temperature control circuit (not shown) for maintaining the electric heating element 274 and consequently the metalic holder 276 at a constant desired temperature. This temperature should be approximately 750-800 F. for best results. Heat insulators 280, 282 and 284 are positioned around the sides and rear of the metalic holder 276 and a mounting block 286 is positioned on the side of heat insulator 284 remote from the metalic holder 276.

The side wall portions 266 and 268 of the housing are secured together by means of a bolt 288 which passes through appropriate holes in the side wall portions and the mounting block 286 and a nut 290. In addition, a C-shaped retaining bar 292 having inwardly flanged edge portions 294 which are adapted to slide in elongated grooves 296 and 298 in side wall portions 266 and 268, respectively, further secures the side wall portions of the housing together. This is accomplished by first tightening nut 290 on bolt 288 so that the side wall portions 266 and 268 taper slightly outwardly towards the bottom edges and then forcing the C-shaped retaining bar 292 downwardly in grooves 296 and 298. In this way. the grooves 296 and 298 act as cammed surfaces for the C-shaped retaining bar 292. A wiring block 300 is then positioned over the end of the edge carbonizing means 220. The wiring block 300 includes a groove 302 adapted to receive wires (not shown] which are connected to an appropriate source of electrical current for the heating element 274. Also contained within groove 302 are wiring terminals 304 and 306 to which the wires not shown are to be connected. In addition, wires 308 and 310 from the electrical heating element 274 are electrically connected to the wiring terminals 304 and 306. The wiring block 300 is securely fastened to the remaining parts of the edge carbonizing means 220 by screws 312 and 314 which pass through appropriate holes in cover member 316, wiring block 300 and mounting block 286.

After the side edges of the envelope are destroyed by side edge carbonizing means 220 and 220. the trans port wheel 202 is indexed from station B to station C where the top edge of the envelope is destroyed by top edge carbonizing means 318. See FIG. 9. The top edge carbonizing means 318 is constructed in substantially the same manner as the side edge carbonizing means 220 and 220' and accordingly a detailed description thereof will not be given. it being understood that the description above of the side edge carbonizing means 220 and 220' applies also to the top edge carbonizing means 318. Furthermore. for clarity, the corresponding elements of the top edge carbonizing means 318 and side edge carbonizing means 220 have been designated by like reference numerals.

Top edge carbonizing means 318 is securely mounted to a horizontally disposed mounting bar 320 by heat insulators 322, 324 and bolts 326 and 328. Each end of mounting bar 320 is mounted for linear slidable movement so that the entire top edge carbonizing means 318 can be moved toward and away from the top edge of the envelope located at station C. Since the driving means located at each end of mounting bar 320 are substantially identical to each other, only one will be described in detail; it being understood that the remaining means is constructed and performs in substantially the same manner as the one being described.

Referring to FIGS. 1, 2 and 9, it can be seen that the end of mounting bar 320 is fixedly secured to a slide bearing 330 which is adapted to slide on slide rod 332. Slide rod 332 is securely fastened to a support bracket 334 which is integral with side frame portions 212. Shock absorbing stopper means 336 and 338 are arranged at each end of slide rod 332 in order to limit the sliding movement of the sliding bearing 330. An outwardly extending pin 340 is integrally connected to slide bearing 330 and is received in the forked end 342 of a lever 344. Lever 344 is pivotally mounted to upright support bracket 334 by pivot pin 346. A counter weight 348 is suspended from the other end of lever 344.

As best seen in FIG. 1, a solenoid 350 is secured to upright support bracket 334 by an L-bracket 352 and engages the upper side of lever 344 at a point between forked end 342 and pivot pin 346. A second solenoid 354 is similarly mounted by an L-bracket 356 to side frame portion 212. Solenoid 354 also engages lever 344 at a point intermediate the forked end 342 and pivot pin 346 but on the underside of lever 344. It can be seen that by this arrangement, when solenoid 350 is energized, it causes lever 344 to move clockwise (as viewed in FIG. 1 against the weight of counterweight 348. This clockwise movement of lever 344 moves pin 340 and slide bearing 330 to the right and downwardly so that top edge carbonizing means 318 engages and destroys the top edge of the envelope located at station C. Similarly, it can be seen that when solenoid 350 is de-encrgized and solenoid 356 is energized. lever 344 is caused to rotate counterclockwise (as viewed in FIG. 1) and top edge carbonizing means 318 is thereby moved away from the top edge of the envelope.

After the top edge of the envelope is destroyed by top edge carbonizing means 318 (an envelope 113C having it) its top edge so destroyed is shown in FIG. the transport wheel 202 is again indexed thereby transporting the envelope from station C to station D where the envelope is removed from the transport wheel 202. This removal is accomplished by a plurality of endless tim- 15 ing conveyor belts 402, 402' and 402". Each timing belt is supported by pulleys 404 and 406 and is posi tively driven by a drive pulley 408. As with many of the other elements of the envelope opening machine. all of the timing conveyor belts are constructed and function in the same manner and accordingly while only one will be described in detail. it being understood that this description applies equally to the remaining timing conveyor belts. This also applies to many of the remaining elements in the envelope opening section. While only one will be described in detail. it will be understood that each of the plurality of similar elements is constructed and functions in the same manner as the one being described.

Referring to FIG. 1, it can be seen that when the envelope in the transport wheel 202 is located at station D. it is substantially horizontal and rests on the horizontally disposed run of conveyor timing belt 402. The conveyor timing belts frictionally engage the bottom side of the envelope and convey the same out of the slot 208 in transport wheel 202 toward the left in FIG. 1. A plurality of endless drive belts such as belt 410 carried by pulleys 412 and 414 are arranged above the conveyor timing belts 402. Accordingly. as the envelope continues its travel, it is conveyed by both upper and lower belts.

Located adjacent the end of timing conveyor belt 402 is a single, wide exit endless conveyor belt 416. Conveyor belt 416 is supported by idler rollers 418. 420. 422, 424 and driving roller 426. Above the conveyor belt 416 is located a plurality of endless driving belts 428 each being supported by an idler pulley 430 and a driving pulley 432. A plurality of friction means 434 which are in the form of fixed rollers are positioned between drive pulleys 414 and 430 and immediately above the beginning of exit conveyor belt 416. These friction means 434 are suspended from a frame 436 which is pivotally mounted by pin 438 to bracket 440 secured to side frame portion 212. As a result of limit stop means (not shown frame 436 is prohibited from pivoting downwardly past the position shown in FIGS. 1 and 10. Frame 436, however, can be pivoted upwardly in order to remove the friction means 434 from the position shown in FIGS. 1 and 10. This is facilitated by a handle 442 which extends towards the front of the envelope opening machine adjacent the top of frame 436. Friction means 434 can also be moved upwardly and downwardly by means of adjusting screw 443 whereby the gap between the friction means 434 and the exit conveyor belt 416 is adjustable.

The gap 433 between friction means 434 and exit conveyor 416 is normally set to be equal to the contents of each envelope and one panel of the envelope.

In other words. the height of gap 433 is equal to the thickness of the envelope entering the gap minus the thickness of one panel of the envelope. Accordingly. as best seen in FIG. I. as the enxelope is conveyed by belts 402 and 410 toward belts 428 and 416. friction means 434 engage the forward end of the top panel 444 of the envelope and begins to peel this top panel 444 back (See FIG. 16). As the envelope continues to be conveyed to the left (as shown in FIG. II. the friction means 434 completley peels the panel 444 of the envelope back. thereby exposing the contents 446 of the envelope. It will be remembered that both side edges and the top (now forward) edge of the envelope have been destroyed by the carbonizing means 220 and 318. A roller 448 located above exit conveyor belt 416 and adjacent the exit end of the envelope opening machine presses the opened envelope against the exit conveyor belt 416 to help ensure that the envelope remains open.

Driving power for all of the drive belts and the conveyor belt 416 of envelope opening section 400 is provided by motor 14 through chain 18. As shown in FIGS. 1 and 2, chain 18 transmits driving power first to a sprocket mounted at the end of rotary shaft 452 which supports driving pulleys 432. Thereafter. the chain drives a sprocket mounted at the end of the rotating shaft which supports driving roller 426. Chain 18 then meshes with a sprocket mounted on idler shaft 456 and meshes with a sprocket mounted at one end of rotating shaft 458 which carries driving pulleys 408. A gear 457 mounted at the other end of shaft 458 meshes with a similar gear 459 on shaft 461 which carries driving pulleys 414. In addition, an endless driving belt 460 transfers the rotary motion of rotating shaft 452 to roller 448 mounted on rotating shaft 462. This is accom plished by means of pulleys 464 and 466 mounted on rotating shafts 452 and 462, respectively. While not specifically shown. it should be understood that appropriate bearings are provided for mounting each of the rotating shafts which support the various pulleys and rollers of the envelope opening section 400.

All of the operations of the envelope opening machine described above are controlled by the control circuit 500 shown in block diagram in FIG. 17. At the heart of the control circuit is a clock circuit 502 which generates a plurality of timed signal pulses. One each of these pulses is delivered to a different one of five driver circuits 504, S06, 508, 510 and 512 which are adapted to drive the various solenoids. In addition, a pulse signal from the clock circuit 502 is transmitted to the stepping index motor 218 for indexing the transport wheel 202. The timing sequence and duration of the pulses generated by clock circuit 502 are shown in FIG. 18.

Referring to FIG. 18, it can be seen that at time T1. a pulse is sent from the clock circuit 502 to the stepping motor control circuit 514 to initiate a ZO-step index of the transport wheel 202. A 20-step index is equal to a movement of 36 of the transport wheel 202. This is equivalent to moving one slot of the transport wheel 202 between two stations since there are ten sets of slots and ten stations. At time T2. clock circuit 502 initiates a pulse to the side seat solenoid drive circuit 504 and to the top seat solenoid drive circuit 508 which si multaneously drive the side edge carbonizing means 220 and 220' and the top edge carbonizing means 318 in towards the envelopes located at stations B and C. respectively. At the same time. i.e.. time T2, the clock circuit 502 discontinues the pulses to the side retract solenoid drive circuit 506 and the top retract solenoid drive circuit 510 thereby releasing the edge carbonizing means from their hold-out positions. At time T3. which is during the time interval that the edge carbonizing means 220. 220' and 318 are destroying the edges of the envelopes. the clock circuit 502 initiates a pulse to the feed solenoid drive circuit 512 which energizes the feed solenoid I34 and feeds an envelope from the hopper 102 to the transport wheel 202 at station A. At time T4. the clock circuit 502 discontinues the pulses to the side and top seat solenoid drive circuits 504 and 508 and simultaneously initiates pulses to the side and top retract solenoid drive circuits 506 and 510. At time T6. the clock circuit 502 again initiates an index pulse to the stepping motor control circuit 514 and the sequence of pulses described above repeats.

It should be noted that the speed of operation of the letter opening machine 10 can be easily changed merely be providing an adjustment means within the clock circuit 502 which will adjust the time interval between the times T4 and T5. The time intervals T1 to T2, T2 to T3 and T3 to T4 should, however, be held constant regardless of the speed of the machine so that a constant burn is achieved.

The control circuit 500 is also provided with means for inhibiting the feeding of envelopes from hopper 102 to the transport wheel 202 in the event that the letter opening machine is operating improperly. The first of these means is an out-of-sync detector circuit 516 which activates inhibit switch 522 whenever a slot 208 in transport wheel 202 fails to be properly positioned beneath the envelope feed section at station A. When inhibit switch 522 is activated by the out-of-sync detector circuit 516, the feed pulse signal from clock circuit 502 is prevented from passing to the feed solenoid drive circuit 512. Out-of-sync detector circuit 516 is controlled by a micro-switch 518 (see FIG. 3) mounted adjacent a disk S19 supported at the end of shaft 213. Disk 519 is adapted to rotate with shaft 213. A plurality of holes or notches 520 are equi-angularly spaced about the disk S19 and are adapted to close the micro-switch 518 the transport wheel 202 is indexed. The microswitch 518 and notches 520 are arranged so that a different one of the notches 520 closes microswitch 518 whenever an envelope receiving slot is properly aligned beneath the envelope feed section 100. Accordingly, should transport wheel 202 become misaligned or out ofsync this will be detected by micro-switch 518 and out-of sync detector circuit 516 will activate inhibit switch 522. It should be readily apparent that a magnetic or photo-electric switch could be used in place of the micro-switch described.

A means is also provided for detecting the presence of an envelope at the envelope opening section 400. The envelopes are sensed by a micro-switch 526 placed beneath the belts on which the envelopes travel (see FIG. 10). Micro-switch 526 has an activator leaf 528 which extends upwardly to a point just above the belt line, i.e. within the plane of movement of the envelopes. Accordingly. an envelope entering the envelope opening section 400 and located in the position shown in FIG. 1 presses the leaf 528 downwardly thereby activating the micro-switch 526. Each time micro-switch 526 is activated, counter 530 is increased to show that another envelope has been opened. In addition. each time micro-switch 526 is activated, it initiates timer circuit 532. Timer circuit 532 is adapted to activate inhibit switch 522 after an elapsed time of approximately one second. In other words, should an envelope remain within the envelope opening section 400 at the position shown in FIG. 1 for more than one second, inhibit switch 522 will be activated thereby inhibiting the feed signal pulse from clock circuit 502 from passing to the feed solenoid drive circuit 512. This condition would indicate that an envelope has become jammed in the envelope opening section 400 and no further envelopes would be fed from the hopper ")2 until the jam were removed.

FIG. ll shows a modified form of an envelope hopper which can be used in place of hopper 102. The hopper shown in FIG. 11 includes a pair of upwardly extending side walls 550 and 552 and a bottom wall 554 connecting the side walls 550 and 552. Arms 556 project inwardly from the top edge of each side wall 550 and 552 adjacent each end of the side walls. Each inwardly extending arm 556 has a plurality of vertical grooves 558 on its inner surface. The hopper also in cludes two movable walls 560 and 562. These walls 560 and 562 have projections 564 adjacent each end of their top edges which projections are adapted to be re ceived in the grooves 558 of arms 556. Accordingly, side walls 560 and 562 can be located in any one of a plurality of positions whereby the hopper can accommodate a wide variety of different size envelopes.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

We claim:

I. An envelope opening machine for automatically opening envelopes and exposing the contents thereof comprising a hopper, a pair of side edge destruction means, a top edge destruction means, means for transferring an envelope from the hopper into alignment with the pair of side edge destruction means, means for moving said pair of side edge destruction means into contact with the side edges of the envelope for destroying said side edges, means for transferring the envelope from the pair of side edge destruction means into alignment with said top edge destruction means, means for moving said top edge destruction means into contact with the top edge of the envelope for destroying said top edge, a discharge conveyor for discharging enve lopes with their contents exposed and means between said discharge conveyor and said top edge destruction means for moving one panel of the envelope to a position wherein the contents of the envelope are exposed,

2. A machine in accordance with claim 1 wherein said pair of side edge destruction means are parallel to one another and are adapted to operate simultaneously for simultaneously destroying both side edges of the en velopes.

3. A machine in accordance with claim 1 wherein each of said edge destruction means includes means for carbonizing an edge of an envelope.

4. A machine in accordance with claim 3 wherein said carbonizing means includes a heater having a surface adapted to contact with the edge of an envelope.

5. A machine in accordance with claim 1 wherein each of said edge destruction means is slidably mounted for rectilinear movement toward and away from a different edge of an envelope.

6. A machine in accordance with claim 5 including solenoid means for moving said edge destruction means.

7. A machine in accordance with claim 1 wherein said transferring means includes a transport wheel having a plurality of envelope receiving slots therein, and means for transferring an envelope from said hopper to one of said slots.

8. A machine in accordance with claim 7 wherein said transport wheel is mounted for rotation about a horizontal axis and including a stepping motor means for rotating said transport wheel about said horizontal axis.

9. A machine in accordance with claim 8 wherein each of said plurality of slots is radially extending and wherein said plurality of slots are equi-angularly spaced about said transport wheel.

10. A machine in accordance with claim 7 wherein said means for transferring an envelope from said hopper includes a rotating feed drive means and a motive means for selectively moving said rotating feed drive means into contact with an envelope in said hopper.

11. A machine in accordance with claim 10 wherein said means for transferring an envelope from said hopper further includes a means for preventing more than one envelope at a time from being transferred from said hopper to said envelope transport wheel.

12. A machine in accordance with claim 9 wherein said pair of side edge destruction means are arranged on either side of said transport wheel and are aligned with a radius of the axis of said transport wheel and wherein said top edge destruction means is arranged parallel to said axis.

13. An envelope opening machine for automatically opening envelopes and exposing the contents thereof comprising a hopper, a pair of side edge destruction means, a top edge destruction means, means for transferring an envelope from the hopper into alignment with the pair of side edge destruction means for destroying the envelope side edges. means for transferring the envelope from the pair of side edge destruction means into alignment with said top edge destruction means for destroying the envelope top edge, a discharge conveyor for discharging envelopes with their contents exposed, and means between said discharge conveyor and said top edge destruction means for moving one panel of the envelope to a position wherein the contents of the envelope are exposed.

14. A machine in accordance with claim 13 wherein said transferring means includes a transport wheel having a plurality of radially disposed envelope receiving slots therein, and means for transferring an envelope from said hopper to one of said slots.

15. A machine in accordance with claim 14 wherein said pair of side edge destruction means are parallel to one another and are adapted to operate simultaneously for simultaneously destroying both side edges of the envelopes. 

1. An envelope opening machine for automatically opening envelopes and exposing the contents thereof comprising a hopper, a pair of side edge destruction means, a top edge destruction means, means for transferring an envelope from the hopper into alignment with the pair of side edge destruction means, means for moving said pair of side edge destruction means into contact with the side edges of the envelope for destroying said side edges, means for transferring the envelope from the pair of side edge destruction means into alignment with said top edge destruction means, means for moving said top edge destruction means into contact with the top edge of the envelope for destroying said top edge, a discharge conveyor for discharging envelopes with their contents exposed and means between said discharge conveyor and said top edge destruction means for moving one panel of the envelope to a position wherein the contents of the envelope are exposed.
 2. A machine in accordance with claim 1 wherein said pair of side edge destruction means are parallel to one another and are adapted to operate simultaneously for simultaneously destroying both side edges of the envelopes.
 3. A machine in accordance with claim 1 wherein each of said edge destruction means includes means for carbonizing an edge of an envelope.
 4. A machine in accordance with claim 3 wherein said carbonizing means includes a heater having a surface adapted to contact with the edge of an envelope.
 5. A machine in accordance with claim 1 wherein each of said edge destruction means is slidably mounted for rectilinear movement toward and away from a different edge of an envelope.
 6. A machine in accordance with claim 5 including solenoid means for moving said edge destruction means.
 7. A machine in accordance with claim 1 wherein said transferring means includes a transport wheel having a plurality of envelope receiving slots therein, and means for transferring an envelope from said hopper to one of said slots.
 8. A machine in accordance with claim 7 wherein said transport wheel is mounted for rotation about a horizontal axis and including a stepping motor means for rotating said transport wheel about said horizontal axis.
 9. A machine in accordance with claim 8 wherein each of said plurality of slots is radially exteNding and wherein said plurality of slots are equi-angularly spaced about said transport wheel.
 10. A machine in accordance with claim 7 wherein said means for transferring an envelope from said hopper includes a rotating feed drive means and a motive means for selectively moving said rotating feed drive means into contact with an envelope in said hopper.
 11. A machine in accordance with claim 10 wherein said means for transferring an envelope from said hopper further includes a means for preventing more than one envelope at a time from being transferred from said hopper to said envelope transport wheel.
 12. A machine in accordance with claim 9 wherein said pair of side edge destruction means are arranged on either side of said transport wheel and are aligned with a radius of the axis of said transport wheel and wherein said top edge destruction means is arranged parallel to said axis.
 13. An envelope opening machine for automatically opening envelopes and exposing the contents thereof comprising a hopper, a pair of side edge destruction means, a top edge destruction means, means for transferring an envelope from the hopper into alignment with the pair of side edge destruction means for destroying the envelope side edges, means for transferring the envelope from the pair of side edge destruction means into alignment with said top edge destruction means for destroying the envelope top edge, a discharge conveyor for discharging envelopes with their contents exposed, and means between said discharge conveyor and said top edge destruction means for moving one panel of the envelope to a position wherein the contents of the envelope are exposed.
 14. A machine in accordance with claim 13 wherein said transferring means includes a transport wheel having a plurality of radially disposed envelope receiving slots therein, and means for transferring an envelope from said hopper to one of said slots.
 15. A machine in accordance with claim 14 wherein said pair of side edge destruction means are parallel to one another and are adapted to operate simultaneously for simultaneously destroying both side edges of the envelopes. 